Light-sensitive layers and process of preparing them



.tion because the paper fiber is Patented May 13, 1930' UNITED STATES MAXIMILIAN PAUL SCHMIDT AND WILHELM KRIEGER,

GERMANY, ASSIGNORS T0 KALLE & 00.

0F GER-MANY IBIEBBICH, GERMANY, A. CORPORATION LIGHT-SENSITIVE LAYERS AND PROCESS OF DE WIESBADEN-IBIEIBBICH, AKTIENGESELLSCHAFT, OF WEISBADEN- PREPARING THEM No Drawing. Application filed July 12, 1928, Serial No. 282,319, and in Germany July 21, 1927.

The present invention relates to the preparation of light-sensitive layers by means 0 diazo compounds.

In the specifications of Letters Patents of the United States No. Leda-A169 granted to Gustav Koegel I and Heinrich Ueuenhaus February 6. 1923, and No. 1,628,279 granted to Maximilian Paul Schmidt and Wilhelm Krieger May 10, 1927, according to which it is possible to apply a diazo compound simultaneously with an azo-dye component on a.

base. In order to prevent a premature coupling of the two components when the material treated therewith is stored for some time, it has been proposed in the said U. S. Patent No. 13%.469 to use for said purpose an ac1d such, for instance, as tartaric acid. Strong mineral acids, which otherwise are capable of preventing the formation of coloring matter cannot be used for the purpose in quesdeteriorated by their action.

\Ve have now found that in order to obviate a premature coupling of the above mentioned components, there may be used with great advantage a mixture of boric acid and an organic acid, for instance tartaric acid or citric acid. By using boric acid in combination with an organic acid it is possible to prevent to a much greater extent the premature formation of coloring matter than when using one of the said two components alone and moreover the paper fiber is not deteriorated thereby.

The addition of the said substances produces the desired eitect both in layers containing the diazo compound in combination with an azo component and in layers containing the diazo compounds alone. This effect appears to be due to the fact that the coupling ot' the diazo compounds with the azo component or with thedecomposition products of the diazo compounds into coloring matter is prevented.

The following examples serve to illustrate our invention, but they are not intended to limit it thereto, the arts being parts by weight:

(1 22 parts of stannic Clloride doublesalt of 4-diazo-1-dimethylaminobenzene to which parts of boric acid and parts of tartaric acid have been added are dissolved together with 2 parts of phloroglucine in 1000 parts of water. lhe matter which separates in a small quantity is filtered ofi and the solution is then applied in the usual manner on a base for instance paper.

(2) 11 parts of zinc chloride double-salt of the diazo-compound obtained from 1- amin0-3-methyle-monoethylaminobenzeneto which 40 parts of tartaric acid and 15 parts of boric acid have been added, is dissolved together with parts of 2.T-dihydroxynaphthalene in one liter of water and this solution is spread in the usual manner on paper or on a film. After having exposed the material to light and developed with gaseous ammonia, positive copies of a deep brown tone on a pure .white ground are obtained.

(3) To 1,2 parts of the diazo compound, obtainable by diazotizing p-aminodiphenylamine in sulfuric solution, are added l parts of tartaric acid and l parts of boric acid and the whoie is then applied on paper. The light-sensitive paper may, after exposure to light, be developed in the usual manner with an azo component for instance [:l-naphthol.

\Ve claim 1. The process of preparing light-sensitive layers by means of diazo compounds, which consists in adding to the diazo compound a mixture of boric acid and a hydroxycarboxylic acid.

2. The process of preparing sensitive layers by means of diazo compounds which consists in adding to'the diazo compound a mixture of boric acid and tartaric acid.

3. The process of preparing sensitive layers by means of diazo compounds which consists in adding to the mixture of a diazo compound and an azo dye component a mixture of boric acid and a hydroxycarboxylic acid.

l. The process of preparing sensitive layers by means of diazo compounds, which consists in adding to the mixture of :1V diazo compound and an azo dyestuit component a mixture of boric acid and tartaric acid.

5. The process of preparing sensitive layers by means of diazo compounds. which consists in adding to a solution of the chloride double salt from 1-amino-3-niethyl-4-monocthylan'iinobcnzene and 2.7-dihydroxynaph thalene a mixtureof 40 parts of tartaric acid and 15 parts of boric acid.

6. As new products, sensitive layers consisting of a diazo compound and a mixture of boric acid and a hydl'oxycarboxylic acid.

7. As new products, sensitive layers consisting of a diazo compound and a mixture of boric acid and tartaric acid.

8. Asnew' products, sensitive layers consisting of a mixture of a diazo compound, an azo dyestufl' component, boric acid and a hydroirycarboxylic acid.

9. As new products, sensitive layers consisting of a mixture of a diazo compound, an azo dyestuif component, boric acid and tartaric acid.

10. As a new product, a sensitive layer consisting of the zinc chloride double salt from 1-amino-3-methyli-monoethylaminobenzene, 2.7 -dihydroxynaphthalene, boric acid and tartaric acid.

In testimony whereof, We aflix our signatures.

MAXIMILIAN PAUL SCHMIDT. WILHELM KRIEGER. 

